Physical, textural, and rheological properties of whipped cream affected by milk fat globule membrane protein

 

This work aims at improving the textural and whipping properties of whipped cream by the addition of milk fat globule membrane protein. The determination of particle size distribution and average diameter of whipped cream showed that the small particle size was shifted to a larger range after milk fat globule membrane protein was added. The average particle size (d_3,2) of whipped cream reached a maximum value of 5.05 µm at 1% milk fat globule membrane protein, while slowly decreased with increasing milk fat globule membrane protein levels from 2% to 5%. In addition, the partial coalescence of fat increased with the increase of milk fat globule membrane protein levels, and the correlation between the whipping time and the overrun of whipped cream was positive. The addition of milk fat globule membrane protein also altered the rheological behaviour of whipped cream, resulting in the increase of modulus G′ and the loss modulus G″. The results also indicated that higher milk fat globule membrane protein level decreased the serum loss of whipped cream while improved its stability. While milk fat globule membrane protein levels had no significant effect on viscosity, its increasing levels effectively improved the hardness, consistency, and viscosity of whipped cream.

KEYWORDS: 

Milk fat globule membrane proteinRheological behaviourTexturePropertiesWhipped cream

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Introduction

Whipped cream is a popular dairy product that is widely used in different food products, such as cakes, desserts, ice creams, creamy coffees, and pastries. Whipped cream is an example of oil-in-water (O/W) emulsion with high fat content (typically 30–40%). It is processed by whipping dairy cream, to which large quality of gas bubbles is incorporated. During the whipping process, fat globules in the cream are absorbed by serum protein and milk fat globule membrane (MFGM) fractions at the air/water interface.^[1,2] A partial crystal network is formed and then the air bubbles are coated; this phenomenon is called the surface-mediated partial coalescence.^[3] In addition to the surface-mediated partial coalescence, churning partial coalescence can also take place between the remaining fat globules in serum.^[4] The partial coalescence plays an important role in stabilizing the structure of whipped cream, resulting in its desirable texture.^[5]

An emulsion system is thermodynamically unstable due to flocculation, creaming, coalescence, phase inversion, and Ostwald ripening.^[6,7] Therefore, some food additives, such as emulsifiers, proteins, or polysaccharides, are usually used to improve the process properties as well as the quality of dairy products. Emulsifiers play an important role in improving the stability of aerated food emulsions by absorbing at the air/water interface, thereby lowering the interfacial tension.^[8] Most milk proteins are excellent emulsifiers, which can prevent fat droplets in whipped cream from re-coalescence during emulsification by rapid adsorption at the oil/water interface and the formation of viscoelastic interfacial membranes.^[9–11] Milk fat globule membrane protein (MFGMP), which mainly consists of mucin 1 (MUC), xanthine oxidase (XO), butyrophilin (BTN), and periodic acid-schiff 6 and 7 (PAS6 and PAS7), is a food ingredient with excellent nutritional value and emulsifying property.^[12] As an emulsifier, MFGMP can not only lead to desirable processing properties, texture, and stability, but also lead to excellent nutritional value of whipped cream products. Like whey protein and casein, MFGMP can absorb at the interface, whereby reduces interfacial tension, forms emulsions and foams, and stabilizes fat droplets and bubbles.^[11]

According to the literature, the majority of studies focused on utilizing whey proteins and sodium caseinate to improve the physicochemical and sensory properties of whipped cream, whereas the application of MFGMP in whipped cream has not been reported. Thus, the aim of this study is to investigate the influence of MFGMP levels on physical characteristics and whipping organoleptic properties of whipped cream. The average particle size, partial coalescence of fat, rheological behaviour, the overrun, serum loss, and texture of whipped cream were determined and compared.